Electromagnetic relay with convertible switch contact modules



July 1, 1969 H. KOERTGE 3,453,571

ELECTROMAGNETIC RELAY WITH CONVERTIBLE SWITCH CONTACT MODULES Sheet Filed Aug. 24, 1967 July 1, 1969 N. H. KOERTGE 3,453,571

ELECTROMAGNETIC RELAY WITH CONVERTIBLE SWITCH CONTACT MODULES Filed Aug. 24, 1967 Sheet 2 014 N. H. KOERTGE Jul 1, 1969 ELECTROMAGNETIC RELAY WITH CONVERTIBLE SWITCH CONTACT MODULES Sheet Filed Aug. 24, 1967 m bN NM C w ww WNW um July 1, 1969 KOERTGE 3,453,571

ELECTROMAGNETIC RELAY WITH CONVERTIBLE SWITCH CONTACT MODULES Filed Aug 24, 1967 Sheet 4 of 4 8h 44a a O Q 8 6mm O O 580E92- United States Patent U.S. Cl. 335-132 6 Claims ABSTRACT OF THE DISCLOSURE A multipart housing comprising a cast metal base structure, one or more insulating members each containing a plurality of individual convertible switch modules, and a cover secured together in a tandem fashion. Panel mounting features are formed integral with the base as are guideways for the movable magnet assembly housed therein. The stationary magnet is supported from one insulating housing member by impact and rebound shock absorbing cushions, Extensions on the movable magnet assembly drive an independently spring biased operator to actuate the switch modules.

Cross-reference to related application- The switch modules used in the relay disclosed herein are more fully described and are claimed in my copending application Ser. No. 663,160 filed Aug. 24, 1967 and assigned to the assignee of the immediate application.

Summary of the invention The relay of this invention is designed to be compact in size, less expensive to manufacture, readily convertible in the field as to contact operating modes and reliable over an extended period of operation. While not limited thereto, the relay disclosed herein is particularly Well suited for use in machine tool control.

It is an object of this invention to provide a more compact electromagnetic relay which has a metal mounting structure for mounting the relay to a panel, such structure being formed integral with a portion of the relay housing.

It is a further object of this invention to provide an electromagnetic relay having novel mounting means for the stationary member of the magnet, said means acting to effectively absorb both impact and rebound forces of the magnet.

It is still a further object of this invention to provide an electromagnetic relay which utilizes individual switch modules as contact pole assemblies, said modules being solely captivated by the relay housing.

These and other objects will become more fully apparent in the following specification and claims when read in conjunction with the accompanying drawings.

Description of the drawings FIGURE 1 is a top plan view of the relay of this invention;

FIG. 2 is an elevational view of the lower side of the relay of FIG. 1;

FIG. 3 is an elevational view of the right-hand side of the relay of FIG. 1 with various housing members thereof exploded;

FIG, 4 is a cross-sectional view taken along line 4-4 of FIG. 1;

FIG. 5 is a cross-sectional view taken along line 55 of FIG. 1;

FIG. 6 is a cross-sectional view taken along line 66 of FIG. 1;

FIG. 7 is a view of the underside of one of the housing members of the relay as indicated by line 77 of FIG. 3;

FIG. 8 is a fragmentary sectional view taken along line 8-8 of FIG. 7;

FIG. 9 is a plan view of the opposite side of the member shown in FIG. 7; and

FIG. 10 is a plan view of another housing member of the relay.

Description of the preferred embodiment With reference to the drawings, the relay of the present invention consists of a multipart housing arranged in a stacked, or tandem fashion. The housing comprises a base structure 2, a switch housing 4 and a molded cover 6. These three major assemblies form the basic electromagnetic switching device of my invention which may contain from one to four poles The relay is designed to have additional structures attached thereto such as a latch, timer, more contact poles, or a combination of contact poles with a latch or timer. While all of these elements have not been shown herein, the device may have from one to twelve contact poles, four poles with a timer, or eight poleswith a latch attachment. The particular version shown in the drawings has a secondary switch housing 8 which provides for an additional four poles of the diS closed modular type to be utilized, the secondary housing 8 being mounted upon the housing 4 in tandem therewith and having the molded cover 6 mounted thereto.

The base structure 2 is a die cast metal member preferably formed of a zinc alloy or the like. In an elfort to reduce the area used by the relay on the panel and to hold the number of parts to a minimum, the panel mounting provisions are conventionally formed integral with the base structure. The use of metal for thi member affords stronger mounting bolt surfaces having the same qualities as those of separate stamped metal mounting plates. The metal structure also has thinner wall thicknesses than an insulating counterpart without any reduction of strength. The thinner wall and integral mounting areas allow the overall dimensions of the base structure to be effectively reduced without sacrificing any desirable qualities of an insulating base structure having a metal mounting plate secured thereto.

With particular reference to FIG. 1, base structure 2 is provided with upper and lower flanges which have a plurality of mounting holes formed therein. The upper flange has a keyed hole 2a formed therein while the lower flange has an open slot 211 and a pair of holes 20 which flank the slot 2b.

The base structure 2 houses the coil element 10 of the device, the element being of the twin coil, encapsulated type with two openings. Coil element 10 rests upon a pair of ledges 2d and 2e of the base 2 to overlie the bottom of the base in spaced relation thereto. Base 2 further has a pair of opposed side walls 2], which are different from the sides containing ledges 2d and 2e, the sides 2 extending upwardly above the coil element 10. The inner surfaces of side walls 2f are suitably configured to provide guides for positioning the coil element 10 therein and for guiding the reciprocal movement of a movable magnet assembly.

The movable magnet assembly comprises a molded insulating carrier member 12 which has a U-shaped movable magnet 14 mounted thereto. Magnet 14 comprises a plurality of L-shaped larninations secured between two frame members in FIGS. 4 and 6. The laminations are arranged to have their horizontal legs adjacent each other and the vertical legs extending upwardly through the openings of coil element 10.

16 by a plurality of rivets as best seen Molded carrier 12 has a central opening which in turn has a pair of shelf portions 12:: formed therein extending toward each other. Magnet 14 rests upon shelf portions 12a and has depending hook portions 16a of frame members 16 extending through the opening below the shelves 12a. A leaf spring 18 overlies the inwardly extending portions of hooks 16a and bears at each of its ends against the undersides of shelves 12 1 to hold the magnet 14 tight against the carrier 12.

Carrier 12 rests upon a shallow ledge formed on the bottom of base structure 2 and is biased thereagainst by a pair of magnet return springs 20. Springs 20 are helical compression springs disposed between depending conical bosses on the underside of coil element and upwardly facing bosses on carrier 12 at diagonally opposite corners of the coil element and carrier. Carrier 12 further has a pair of upwardly extending 'arms 12b, the exterior of which fit closely within grooves formed on the interior of walls 2 of base 2 to guide the carrier for reciprocal movement therein. Arms 12b extend alongside coil element 10 at its reduced mid-section, the interior surfaces of arms 12b conforming to the V-shaped configuration created at the center of the substantially figure-eight coil.

A molded, insulating housing member 4 is secured to the base structure 2 by screws 22 at the four corners thereof. Housing member 4 has depending posts at the four corners thereof which define a first pair of opposed recessed sidewalls 4a which overlie and mate with walls 2 and a second pair of opposed recessed sidewalls 4b which overlie and are spaced from ledges 2d and 22. The sidewalls 4b overlie the upper surface of coil element 10 at its exposed ends, one of the ends having coil wiring terminals 24 molded thereon.

A pair of helical compression springs 26 are forced over depending bosses formed on the underside of housing member 4 and bear against the upper surface of coil element 10 at diagonally opposite corners thereof to firmly hold the coil against the ledges 2d and 2e of the base structure in operation. Springs 26 are made sufficiently strong to hold coil element 10 down against the ledges without vibration or chattering during normal operating conditions.

A stationary magnet member 28 is mounted to the underside of housing 4, the member 28 also being of a laminated construction. The ends of stationary magnet 28 are shaped to have a configuration which may be described as analogous to the thumb and fingers of a human hand, particularly when viewed as in FIG. 6. Each end of the magnet has an upwardly turned finger portion 28a and an outwardly extending thum portion 28b which is slightly above the end of the finger portion. With this configuration the ends grip a pair of mounting cushions 30 with the thumb portions 28b overlying a portion of the cushion 30* and the finger portions 28a abutting the undersides thereof.

Cushions 30 are made of an impact absorbing rubber impregnated laminated fibre material such as that manufactured under the name Fabreeka or the like. Cushions 30 are rectangular in shape and tfit within pockets 40 (FIG. 8) formed in the underside of housing member 4. A pair of steel clamps 32 underlie the cushions 30 and are secured to the member 4 by screws 34. Clamps 32 have rectangular openings 32a formed therein through which the upturned finger portions 28a of stationary magnet 28 pass to abut the cushions 30. The upper, inner edges of cushions 30 extend slightly beyond the portions of the housing in which recesses 40 are formed and thereby create protruding ledges upon which the thumb portions 28b of magnet 28 rest (FIG. 6). The clamps 32 may be seen to support the overhanging portion of the cushions 30 from the underside.

A substantially flat, insulating switch operator 36 is positioned within the housing member 4 transversely of the magnet 28 so that its ends overlie the ends of upwardly extending arms 12b of carrier 12. A pair of helical compression springs 38 bear between a surface of the housing member 4 and the upper surface of operator 36 to bias the latter against the upper surface of stationary magnet member 28 (FIG. 6). Operator 36 is guided for reciprocal movement within the housing member 4 by four rectangular bosses 4d molded within the cavity as seen best in FIG. 7. The ends of arms 12b engage the underside of operator 36 to reciprocally move the latter in response to movement of the movable magnet 14, while the springs 38 cause the operator 36 to follow upon the return of the magnet 14. The upper surface of operator 36 has a centrally located boss portion 36a which in turn has a threaded stud 40 molded therein for reasons that will become more apparent later. Also formed on the upper surface of operator 36 are a plurality of pads 36b which are engaged by the switch actuators as will be described later.

Referring now to FIG. 9, which is a plan view of the upper side of housing member 4, it may be seen that the latter has a plurality of switch pockets 4e formed therein. Each pocket 4e has a central, rectangular opening in the bottom thereof which communicates with the lower portion of the housing member and operator 36, previously described. The pads 36b of the operator are formed to be alined with the central openings of each pocket.

Pockets 4e are shaped to receive complementally shaped switch modules 42 therein by insertion from above. A detailed description of the switch modules 42 may be obtained from the earlier mentioned copending application, while the same shall be dealt with only briefly herein.

Each switch module 42 comprises a transparent insulating case which closely conforms to the shape of the pockets 4e. A pair of terminals 42a extend outwardly of the opposite ends of the case while the inner ends of termnials 42a extend within the switch cavity to serve as stationary contacts which are arranged to be bridged by a movable bridging contact 42b. The latter is resiliently mounted to a contact carrier 42c which extends through openings in the top and bottom of the switch module case. The carrier 420 is guided for movement within the case by bearings 42d at the upper and lower surfaces of the case. Bearings 42d have internal flanges to prevent their removal from the switch module. Each switch module contains its own return spring 42c which bears between one of the bearings 42d and a shoulder formed on the carrier 42c, and further contains its own contact pressure spring 429 which bears between the other bearing 42d and the movable bridging contact 42b.

As seen in FIGS. 4 and 5, the lower bearings 42d and the corresponding ends of carriers 42c extend through the central openings of pockets 42, the carrier ends abutting the pads 36b of operator 36 to be moved thereby. The upper bearings 42d of switch modules 42 are held flush with the upper surface of the module case by the underside of either cover 6 or, as illustrated, the underside of an auxiliary switch housing member 8. These undersides are shaped to hold the bearings 42d at the four corners thereof, while providing space to allow the corresponding end of the carrier 420 to move upwardly therethrough. As the switch modules are shown in the drawings, the contacts thereof assume a normally open condition. In operation of the device the carriers 42c are driven upward against the bias of springs 426 which bear between the held bearings 42d and the shoulders on the carriers. Contact pressure is afforded the bridging contact by the springs 42 The switch modules may be converted to normally closed switches by removing them from the housing, inverting them, changing the wiring screws to the other side of the terminals, and reinserting the modules in the pockets. The upper bearings 42d are again held flush I with the surface of theinsulating case of the module,

causing the bridging contacts 42b to engage the stationary contacts under pressure of springs 42 The latter serves also as the return spring in the normally closed mode of operation for the modules.

While the first mentioned housing member 4 may house up to four switch modules, or contact poles, an additional one to four poles may be achieved by securing an auxiliary housing member 8 to the upper surface of housing 4. Auxiliary housing member 8 is secured to housing member 4 by :a pair of screws 46 which take into threaded alined openings in the upper surface of housing member 4 (FIG. 6). The auxiliary member 8 is provided with a pair of depending bosses 8a and 8b, the former being substantially smaller than the latter, to mate with corresponding holes 4 and 4g, respectively, formed in the upper surface of housing member 4 to in sure correct replacement thereon.

With particular reference to FIG. 10, the upper surface of auxiliary housing member 8 is provided with a plurality of switch module pockets 80 similar to the pockets 4e. The central openings at the bottoms of pockets 8c differ from those of pockets 4e in that the former have a cross-like opening instead of rectangular to receive and guide insulators 44. The insulators are substantially square when viewed from the top and have a pair of outwardly extending portions which terminate in resilient ears 44a. Insulators 44 are pressed through the central openings of pockets 8c, the ears 44m being cammed inwardly by the edges of the opening until they pass below the bottomwall of the pockets. The ears 44a then spring outwardly to interfere with the lower wall of the pockets to prevent removal of the insulators from the housing (FIGS; 5 and 10). Insulators 44 normally rest upon the lower wall of housing member 8 (FIG. 4), but are afforded linear movement within the housing, such movement being guided by rail portions 8d molded on either side of the central openings and bearing against the outwardly extending portions of the insulators (FIGS. 5 and 10).

The insulators 44 are alined within the openings to be engaged by the contact carriers 420 of switch modules in the housing member 4. The carriers of the switch modules of housing member 8 engage the upper surface of insulators 44 and are thereby driven in response to movement of the carriers of the lower modules.

Auxiliary housing member 8 and the switch modules 42 therefor are somewhat shorter in length than housing member 4 and its modules to allow easy access to the switch terminals of housing member 4 from above. The shorter switch module length is achieved by using shorter terminals 42g for the switch modules used in auxiliary housing member 8. Also, since the switch modules for housing members 4 or 8 are otherwise the same, one or more modules having the longer terminals 42:: could be accidently placed in the shorter auxiliary housing member 8 in which case the terminals 42:: would extend beyond the insulating barriers formed between the switch pockets. To prevent this, terminals 42a have been provided with short wings 4211 (FIG. 9) adjacent the switch module case. Wings 42h will interfere with nibs 8e formed on the sides of the pockets 8c of auxiliary housing member 8 to block insertion of an improper module into the pocket 8c.

Cover member 6 is secured to the member 8 by a pair of screws 48 which take into threaded openings formed in the heads of screws 46. The underside of cover 6 is similarly configured to the underside of housing member 8 so that it holds the bearings 42d of the switch modules 42 flush with the upper surfaces of the module cases. Cover 6 also has depending bosses 6a and 6b which are identical to the bosses 8a and 8b of auxiliary housing member 8. The upper surface of member 8 is provided with holes 8 and 8g which correspond respectively with identical holes 4 and 4g to receive the bosses 6a and 6b.

The housing members 4, 8 and 6 are provided with vertically alined central holes 4h, 8k and 60, respectively, as best seen in FIGS. 4 and 6.

A11 insulating rod 50, having threaded openings at each end thereof, is inserted through the alined openings and threaded upon the stud 40 of operator 36. A knurled, shouldered screw 52 is threaded into the opposite end of rod 50 with a colored plastic sleeve 54 disposed therebetween. The knurled portion of screw 52 extends above the surface of cover 6 to be grasped and pulled outwardly to manually operate the switch modules of the relay if desired. It should be seen that in such manual operation of the device, it is only necessary to overcome the relatively light spring pressure of the springs 38 and not that of the heavier magnet return springs 20 since the operator 36 is not rigidly connected to the movable magnet assembly.

A visual indication of the state of the relay is alforded by the colored sleeve 54. When the relay is in its deenergized condition the sleeve 54 is disposed totally below the surface of cover 6. Upon energization, the sleeve 54 extends above the surface of the cover to afford a ready indication to a viewer at some distance that the relay is operated or energized.

Operation In operation the coil terminals 24 of the relay are connected to some source of electrical supply through the contacts of a control member such as a limit switch or the like. The terminals 42a and 42g of the various switch modules are connected to the various elements desired to be controlled by the relay.

Upon energization of the coil element 10 the movable magnet member 14 is attracted to the stationary magnet member 28. The larger and heavier magnet member 14 is chosen to be the movable member to provide a movement of less velocity and thereby seats against the stationary member with a duller, but more positive, blow than would occur if the lighter magnet member were the movable member. Arms 12b of the magnet carrier drive the operator 36 against the bias of springs 38 to actuate the switch modules 42. Contact bounce in the modules is greatly reduced due to the slower speed of the movable magnet member 14.

The impact of member 14 seating against member 28 is absorbed by the portions of cushions 30 which lie within the openings 32a of clamps 32. The upturned [finger portions 28a of member 28 compress the above mentioned area of cushions 30 directly against the housing member 4. A certain amount of impact force is transferred into rebound force which is also absorbed by the cushions 30. The rebound force is delivered to the cushions by the thumb extensions 28b which compress the overhanging areas of cushions 30 against the underlying portions of clamps 32.

Upon deenergization of coil element '10 the magnet loses its attractive strength and the magnet return springs 20 drive the carrier 12 against the ledge in the bottom of base member 2, carrying with it the movable magnet member 14. When the relay is oriented as it is in the drawings, springs 20 would be aided strongly by gravity. However, the relay is most often mounted on a vertical panel which would cause a ninety degree translation of the device as shown. In this instance it is quite necessary that the return springs 20 be of sufiicient strength to drive members 12 and 14 back horizontally against the ledge in base 2.

Operator 36 follows the return movement of carrier arms 12b due to the influence of springs 38. Likewise, the contact carriers 420 of the switch modules 42 and the insulators 44 follow the return movement due to the return spring pressure of the individual switch modules.

An electromagnetic relay has thus been disclosed in which attraction of the magnet members causes the movable member of the relay to be displaced to operative positions, and wherein the release of the magnet members allows all movable parts to be spring returned to their original positions. The relay as disclosed is provided with a novel shock absorbing means which absorbs both the impact and rebound forces present upon the seating of the magnet members. The contact poles take the form of individual switch modules which are convertible by inversion to change the contact operating mode and contain their own return and contact pressure springs.

It is to be understood that the embodiment disclosed herein is merely exemplary of a preferred way of carrying out the invention and that the same is susceptible to various modifications without departing from the scope of the appended claims.

I claim:

1. In an electromagnetic switching device, the combination comprising: a housing; an operating coil mounted in said housing; a movable magnet assembly mounted for reciprocal movement in said housing; spring means biasing said movable magnet assembly to a normal position within said housing; switching means mounted in said housing comprising alined pairs of stationary contacts, cooperating movable bridging contacts and contact carrier means therefor; operator means movable in response to movement of said movable magnet assembly to move said contact carrier means to cause contact actuation of said switching means; a pair of shock absorbing cushion members secured against ledges formed in said housing at opposite sidewalls thereof, each of said cushion members extending beyond its associated ledge and toward the other of said pair of cushion members; and a stationary magnet member suspended from said pair of cushion members, said stationary magnet member having first portions at its opposite ends which overlie and bear upon said cushion members at the portions thereof extending beyond said ledges, and said stationary magnet further having second portions at its opposite ends which bear against said cushion members at arespective side thereof opposite that at which said first portion bears. I

2. The combination according to claim 1 wherein said cushion members are secured against said ledges formed in said housing by clamp members, said clamp members extending across said cushion members and being rigidly secured at their opposite ends to said housing to secure said cushion members against said ledges, said clamps having apertures therein through which said stationary magnet second portions extend to bear against said cushion members.

3. The combination according to claim 1 wherein said operator means includes a rod member extending exteriorly of said device through an opening in said housing, said operator means being movable independently of said movable magnet assembly, second spring means biasing said operator means for following movement with said movable magnet assembly, and whereby manual movement of Said rod member moves said operator means independently of said movable magnet assembly and against the sole bias of said second spring means to actuate said switching means.

4. The combination according to claim 1 wherein:

said housing comprises a plurality of separate members secured together in tandem, at least one of which has a plurality of pockets formed in one side thereof having openings in the bottom thereof communicating with the opposite side of said member;

said switching means includes individually complete switch modules inserted within said pockets, said switch modules each comprising an insulating case having a pair of aligned stationary contacts and a movable bridging contact cooperably mounted therein and a contact carrier operatively connected to said bridging contact and protruding externally of said case for external actuation of said switch module contacts;

" said operator means engages said contact carriers of said inserted switch modules through said openings in the bottoms of said pockets; and

said switch modules are retained within said pockets by an adjacent housing member.

5. The combination according to claim 4 wherein pockets are provided in an adjacent pair of housing members, said housing members having switch modules inserted within said pockets, and wherein said contact carriers of said switch modules in one housing member are tandemly alined with and operated by the contact carriers of said switch modules in the other housing members.

6. The combination according to claim 5 together with an insulating member disposed between the contact cartiers of a tandemly alined pair of switch modules, said member being guided for movement responsive to that of said contact carriers by linearly extending rail means formed within said one housing member adjacent said openings in said pockets.

References Cited UNITED STATES PATENTS 3,215,800 11/1965 Hurter 335l32 BERNARD A. GILHEANY, Primary Examiner.

H. BROO'ME, Assistant Examiner.

US. Cl. X.R. 

